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	<head>
		<title>three.js webgpu - instance path</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="example.css">
	</head>
	<body>

		<div id="info">
			<a href="https://threejs.org/" target="_blank" rel="noopener" class="logo-link"></a>

			<div class="title-wrapper">
				<a href="https://threejs.org/" target="_blank" rel="noopener">three.js</a><span>Instance Path</span>
			</div>

			<small>
				Rendering and animating instances along a path.
			</small>
		</div>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.webgpu.js",
					"three/webgpu": "../build/three.webgpu.js",
					"three/tsl": "../build/three.tsl.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three/webgpu';

			import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
			import { RoomEnvironment } from 'three/addons/environments/RoomEnvironment.js';
			import { Inspector } from 'three/addons/inspector/Inspector.js';

			import { abs, add, instancedBufferAttribute, positionLocal, mod, time, sin, vec3, select, float, screenUV, color } from 'three/tsl';

			let camera, scene, renderer, controls;

			const count = 1000;

			init();

			async function init() {

				camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 0.01, 100 );
				camera.position.z = 15;

				scene = new THREE.Scene();
				scene.backgroundNode = screenUV.distance( .5 ).remap( 0, 0.65 ).mix( color( 0x94254c ), color( 0x000000 ) );

				// generate a path representing a heart shape

				const x = 0, y = 0;

				const path = new THREE.Path()
					.moveTo( x - 2.5, y - 2.5 )
					.bezierCurveTo( x - 2.5, y - 2.5, x - 2, y, x, y )
					.bezierCurveTo( x + 3, y, x + 3, y - 3.5, x + 3, y - 3.5 )
					.bezierCurveTo( x + 3, y - 5.5, x + 1, y - 7.7, x - 2.5, y - 9.5 )
					.bezierCurveTo( x - 6, y - 7.7, x - 8, y - 5.5, x - 8, y - 3.5 )
					.bezierCurveTo( x - 8, y - 3.5, x - 8, y, x - 5, y )
					.bezierCurveTo( x - 3.5, y, x - 2.5, y - 2.5, x - 2.5, y - 2.5 );

				// generate instanced ico-spheres along the path
			
				const geometry = new THREE.IcosahedronGeometry( 0.1 );
				const material = new THREE.MeshStandardNodeMaterial();

				const mesh = new THREE.Mesh( geometry, material );
				mesh.position.set( 2.5, 5, 0 );
				mesh.count = count;
				mesh.frustumCulled = false;

				scene.add( mesh );

				// instance data

				const v = new THREE.Vector3();
				const c = new THREE.Color();

				const positions = [];
				const times = [];
				const seeds = [];
				const colors = [];

				for ( let i = 0; i < count; i ++ ) {

					const t = i / count;
					path.getPointAt( t, v );

					v.x += ( 0.5 - Math.random() );
					v.y += ( 0.5 - Math.random() );
					v.z = ( 0.5 - Math.random() );

					positions.push( v.x, v.y, v.z );
					times.push( t );
					seeds.push( Math.random() );

					c.setHSL( 0.75 + ( Math.random() * 0.25 ), 1, 0.4 );

					colors.push( c.r, c.g, c.b );

				}

				const positionAttribute = new THREE.InstancedBufferAttribute( new Float32Array( positions ), 3 );
				const colorAttribute = new THREE.InstancedBufferAttribute( new Float32Array( colors ), 3 );
				const timeAttribute = new THREE.InstancedBufferAttribute( new Float32Array( times ), 1 );
				const seedAttribute = new THREE.InstancedBufferAttribute( new Float32Array( seeds ), 1 );

				// TSL

				const instancePosition = instancedBufferAttribute( positionAttribute );
				const instanceColor = instancedBufferAttribute( colorAttribute );
				const instanceSeed = instancedBufferAttribute( seedAttribute );
				const instanceTime = instancedBufferAttribute( timeAttribute );

				const localTime = instanceTime.add( time );
				const modTime = mod( time.mul( 0.4 ), 1 );
			
				const s0 = sin( localTime.add( instanceSeed ) ).mul( 0.25 );
			
				const dist = abs( instanceTime.sub( modTime ) ).toConst(); // modTime and instanceTime are in the range [0,1]
				const wrapDist = select( dist.greaterThan( 0.5 ), dist.oneMinus(), dist ).toConst(); // the normalized distance should wrap around 0/1
				const s1 = select( wrapDist.greaterThan( 0.1 ), float( 1 ), wrapDist.remap( 0, 0.1, 3, 1 ) ); // compute a scale in a range around the current interpolated value
			
				const offset = vec3( instancePosition.x, instancePosition.y.add( s0 ), instancePosition.z ).toConst( 'offset' );
				material.positionNode = add( positionLocal.mul( s1 ), offset );
				material.colorNode = instanceColor;
			
				//

				renderer = new THREE.WebGPURenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				renderer.toneMapping = THREE.NeutralToneMapping;
				renderer.inspector = new Inspector();
				document.body.appendChild( renderer.domElement );

				await renderer.init();

				const pmremGenerator = new THREE.PMREMGenerator( renderer );
				scene.environment = pmremGenerator.fromScene( new RoomEnvironment(), 0.04 ).texture;

				controls = new OrbitControls( camera, renderer.domElement );
				controls.enableDamping = true;

				//

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			function animate() {

				controls.update();

				renderer.render( scene, camera );

			}

		</script>

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